A cascade preheating energy storage steam heat pump unit and its control method

Abstract

This invention relates to the field of steam heat pump unit technology, and particularly to a cascade preheating energy storage steam heat pump unit and its control method. It integrates energy storage and flash evaporation, achieving high utilization, system simplicity, and space saving. The unit can seamlessly switch between energy storage operation, energy storage steam generation, and direct steam generation operation modes. After the stored hot water is used up, it can automatically switch to direct steam generation mode as needed, facilitating steam output adjustment and providing comfortable and convenient use. During long-term shutdowns, the cooled hot water in the energy storage flash tank can be directly preheated, and new water entering from the inlet can be preheated progressively through the first and second heat exchangers. The use of refrigerant liquid makeup water cooling significantly improves the refrigerant's liquid subcooling. The various systems complement each other, greatly improving the energy efficiency ratio of the heat pump system, enhancing operational reliability while saving energy.

Description

Technical Field

[0001] This invention relates to the field of steam heat pump unit technology, and in particular to a cascade preheating energy storage steam heat pump unit and its control method. Background Technology

[0002] Currently, there are general heat storage heat pump steam engines that can use refrigerant compression and circulation to produce high-temperature hot water and store it in a heat storage tank. Then, the refrigerant compression and heat pump system are shut down. When needed, the high-temperature hot water in the heat storage tank is taken out to a flash tank for evaporation to generate steam.

[0003] However, such ordinary thermal storage heat pump steam engines have the following problems: 1. The dual setup of thermal storage tank and flash tank results in high cost, system complexity, and wasted space; 2. Thermal storage operation and steam generation cannot be carried out simultaneously. The stored hot water can only be used to generate steam after the high-temperature hot water has been stored. When the stored hot water is used up, it is not possible to directly replenish the steam using a refrigerant compressor. The switching between thermal storage, storage, and direct heating is inflexible and inconvenient for adjusting steam output; 3. When the machine is shut down, the water that has cooled in the flash tank cannot be returned to the thermal storage tank for reheating. As a result, when the machine is restarted, the water temperature in the flash tank is too low to boil and generate steam; 4. The liquid temperature at the condenser outlet is high and the subcooling is low, resulting in low overall energy efficiency and high energy consumption. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a cascade preheating energy storage steam heat pump unit and its control method, which is low in cost, simple in system, space-saving, and can freely switch between heat storage, storage use and direct heating, realizing energy storage and flash evaporation in one unit, facilitating steam output adjustment, and can directly preheat the cooled hot water in the energy storage flash tank when the unit is shut down for a long time, thereby improving the subcooling of the refrigerant liquid, with high energy efficiency ratio, high reliability and low energy consumption.

[0005] The technical solution adopted in this invention is as follows:

[0006] A cascade preheating and energy storage steam heat pump unit includes a refrigerant circulation system, a cascade preheating system, an energy storage and steam generation system, and a hot water circulation system;

[0007] The refrigerant circulation system includes a refrigerant compressor, condenser, expansion valve, and evaporator connected in sequence through pipes to form a closed loop;

[0008] The cascade preheating system includes an inlet, a first water pump, and a heat exchange assembly connected in sequence by pipes. The heat exchange assembly is connected between the condenser and the expansion valve.

[0009] The energy storage and steam generation system includes an energy storage flash tank, a second regulating valve, a steam compressor, and a steam outlet, which are connected in sequence by pipelines.

[0010] The hot water circulation system includes a second water pump and a first regulating valve. Both the second water pump and the first regulating valve are connected to the energy storage flash tank and the condenser through pipelines to form a closed loop.

[0011] The heat exchange components are connected between the second water pump and the energy storage flash tank via pipes.

[0012] Preferably, the heat exchange assembly includes a first heat exchanger and a second heat exchanger connected to each other. The first heat exchanger is connected between the condenser and the expansion valve. The first water pump and the second heat exchanger are connected through the first heat exchanger. The second heat exchanger is connected between the second water pump and the energy storage flash tank through a pipeline. The oil inlet and outlet of the refrigerant compressor are connected to the oil inlet and outlet of the second heat exchanger through oil pipes to form a closed loop.

[0013] Preferably, a bypass valve is connected between the oil outlet pipe and the oil inlet pipe of the refrigerant compressor.

[0014] Preferably, it also includes an electrical control system, which includes:

[0015] Sensor components used to sense temperature, pressure, or liquid level at a target location;

[0016] The sensor data acquisition module is connected to the sensor assembly and is used to acquire the data sensed by the sensor assembly.

[0017] The central controller is connected to the sensor data acquisition module and is used to process and analyze the acquired data and send control commands to the controlled devices through preset control parameters. The controlled devices include a water pump speed controller that controls the opening of the first water pump, a refrigerant compressor, the first water pump, the second water pump, the first regulating valve, and the second regulating valve, all of which are controlled devices.

[0018] The display operation module is connected to the central controller and is used to set preset control parameters.

[0019] Preferably, the sensor assembly includes a third temperature sensor, a fifth temperature sensor, a first pressure sensor, a second pressure sensor, a third pressure sensor, and a liquid level sensor. The third temperature sensor is installed on the connecting pipe between the second regulating valve and the steam compressor, the fifth temperature sensor is installed at the bottom of the energy storage flash tank, the first pressure sensor is installed on the connecting pipe between the condenser and the first regulating valve, the second pressure sensor is installed on the connecting pipe between the energy storage flash tank and the second regulating valve, the third pressure sensor is installed on the connecting pipe between the second regulating valve and the steam compressor, and the liquid level sensor is installed inside the energy storage flash tank.

[0020] Preferably, the sensor assembly also includes a first temperature sensor, a second temperature sensor, a fourth temperature sensor, a sixth temperature sensor, and a fourth pressure sensor. The first temperature sensor is installed on the connecting pipe between the second water pump and the condenser. The second temperature sensor is installed on the connecting pipe between the condenser and the first regulating valve. The fourth temperature sensor is installed on the connecting pipe between the refrigerant compressor oil outlet and the second heat exchanger oil interface. The sixth temperature sensor is installed on the top of the energy storage flash tank. The fourth pressure sensor is installed on the connecting pipe between the steam compressor and the steam outlet.

[0021] The present invention also provides a control method for a cascade preheating energy storage steam heat pump unit. The display operation module is equipped with three operating modes corresponding to three different preset control parameters, including energy storage operation mode, energy storage steam generation mode and direct steam generation mode, and the three operating modes can be switched freely.

[0022] As a preferred embodiment, when the energy storage operation mode is selected, the central controller controls the second regulating valve to close and controls the refrigerant compressor, the first water pump, and the second water pump to start working;

[0023] The actual liquid level measured by the liquid level sensor is H. 实测液位 The liquid level setpoint is H. 液位设定 The control accuracy is H 设定精度 Set H on the display operation module 液位设定 and H 液位精度 ;

[0024] When H 液位设定 -H 设定精度 ≤H 实测液位 ≤H 液位设定 +H 设定精度 At this time, the water pump speed regulator remains in its original state;

[0025] When H 实测液位 >H 液位设定 +H 设定精度 At that time, the central controller controls the pump speed regulator to reduce the opening of the first pump;

[0026] When H 实测液位 <H 液位设定 -H 设定精度 At that time, the central controller controls the water pump speed regulator to increase the opening of the first water pump;

[0027] The actual measured pressure of the first pressure sensor is P. 实测压力1 The pressure setpoint is P. 压力设定1 The control accuracy is P 设定精度1 Set P on the display operation module 压力设定1 and P 设定精度1 ;

[0028] When P压力设定1 -P 设定精度1 ≤P 实测压力1 ≤P 压力设定1 +P 设定精度1 At this time, the first regulating valve remains in its original state;

[0029] When P 实测压力1 >P 压力设定1 +P 设定精度1 At that time, the central controller controls the first regulating valve to increase its opening.

[0030] When P 实测压力1 <P 压力设定1 -P 设定精度1 At that time, the central controller controls the first regulating valve to reduce its opening.

[0031] The actual test temperature of the fifth temperature sensor is T. 实测温度5 The temperature setpoint is T. 温度设定5 The control accuracy is T 设定精度5 Set T on the display operation module 温度设定5 and T 设定精度5 ;

[0032] When T 温度设定5 -T 设定精度5 ≤T 实测温度5 ≤T 温度设定5 +T 设定精度5 At this time, the refrigerant compressor remains in its original state;

[0033] When T 实测温度5 >T 温度设定5 +T 设定精度5 At that time, the central controller controls the refrigerant compressor to operate under load;

[0034] When T 实测温度5 <T 温度设定5 -T 设定精度5 At that time, the central controller controls the refrigerant compressor to load.

[0035] As a preferred option, when the energy storage steam generation mode is selected, the central controller controls the second regulating valve to open and controls the refrigerant compressor, the first water pump, and the second water pump to stop.

[0036] The actual liquid level measured by the liquid level sensor is H. 实测液位 The liquid level stop function uses the energy storage mode setting value H. 液位停止用储能设定 Set H on the display operation module 液位停止用储能设定 ;

[0037] When H 实测液位 >H 液位停止用储能设定 At that time, continue operating in the energy storage steam generation mode;

[0038] When H 实测液位 ≤H液位停止用储能设定 At that time, the control unit switches to direct steam generation mode;

[0039] Set the steam control target to pressure or temperature on the display operation module;

[0040] When steam is set to be controlled by pressure;

[0041] The actual test pressure of the third pressure sensor is P. 实测压力3 The pressure setpoint is P. 压力设定3 The control accuracy is P 设定精度3 Set P on the display operation module 压力设定3 and P 设定精度3 ;

[0042] When P 压力设定3 -P 设定精度3 ≤P 实测压力3 ≤P 压力设定3 +P 设定精度3 At this time, the second regulating valve remains in its original state;

[0043] When P 实测压力3 >P 压力设定3 +P 设定精度3 At that time, the central controller controls the second regulating valve to reduce its opening.

[0044] When P 实测压力3 <P 压力设定3 -P 设定精度3 At that time, the central controller controls the second regulating valve to increase its opening.

[0045] When steam is set to be controlled by temperature;

[0046] The actual temperature measured by the third temperature sensor is T. 实测温度3 The temperature setpoint is T. 温度设定3 The control accuracy is T 设定精度3 Set T on the display operation module 温度设定3 and T 设定精度3 ;

[0047] When T 温度设定3 -T 设定精度3 ≤T 实测温度3 ≤T 温度设定 3+T 设定精度3 At this time, the second regulating valve remains in its original state;

[0048] When T 实测温度3 >T 温度设定3 +T 设定精度3 At that time, the central controller controls the second regulating valve to reduce its opening.

[0049] When T 实测温度3 <T 温度设定3 -T设定精度3 At that time, the central controller controls the second regulating valve to increase its opening.

[0050] Preferably, when the direct steam generation mode is set, the central controller controls the second regulating valve to open, and controls the refrigerant compressor, the first water pump and the second water pump to open.

[0051] The actual liquid level measured by the liquid level sensor is H. 实测液位 The liquid level setpoint is H. 液位设定 The control accuracy is H 设定精度 Set H on the display operation module 液位设定 and H 液位精度 ;

[0052] When H 液位设定 -H 设定精度 ≤H 实测液位 ≤H 液位设定 +H 设定精度 At this time, the water pump speed regulator remains in its original state;

[0053] When H 实测液位 >H 液位设定 +H 设定精度 At that time, the central controller controls the pump speed regulator to reduce the opening of the first pump;

[0054] When H 实测液位 <H 液位设定 -H 设定精度 At that time, the central controller controls the water pump speed regulator to increase the opening of the first water pump;

[0055] Set the steam control target to pressure or temperature on the display operation module;

[0056] When steam is set to be controlled by pressure;

[0057] The actual test pressure of the third pressure sensor is P. 实测压力3 The pressure setpoint is P. 压力设定3 The control accuracy is P 设定精度3 Set P on the display operation module 压力设定3 and P 设定精度3 ;

[0058] When P 压力设定3 -P 设定精度3 ≤P 实测压力3 ≤P 压力设定3 +P 设定精度3 At this time, the refrigerant compressor remains in its original state;

[0059] When P 实测压力3 >P 压力设定3 +P 设定精度3 At that time, the central controller controls the refrigerant compressor to operate under load;

[0060] When P 实测压力3 <P 压力设定3 -P 设定精度3 At that time, the central controller controls the refrigerant compressor to load;

[0061] When steam is set to be controlled by temperature;

[0062] The actual temperature measured by the third temperature sensor is T. 实测温度3 The temperature setpoint is T. 温度设定3 The control accuracy is T 设定精度3 Set T on the display operation module 温度设定3 and T 设定精度3 ;

[0063] When T 温度设定3 -T 设定精度3 ≤T 实测温度3 ≤T 温度设定3 +T 设定精度3 At this time, the refrigerant compressor remains in its original state;

[0064] When T 实测温度3 >T 温度设定3 +T 设定精度3 At that time, the central controller controls the refrigerant compressor to operate under load;

[0065] When T 实测温度3 <T 温度设定3 -T 设定精度3 At that time, the central controller controls the refrigerant compressor to load.

[0066] The beneficial effects of this invention are as follows:

[0067] This cascade preheating energy storage steam heat pump unit integrates energy storage and flash evaporation, offering high utilization, system simplicity, and space saving. The unit seamlessly switches between energy storage operation, energy storage steam generation, and direct steam generation modes. Once the stored hot water is depleted, it automatically switches to direct steam generation mode as needed, facilitating steam output adjustment and providing comfortable and convenient operation. During extended shutdowns, cooled hot water in the energy storage flash tank can be directly preheated, and newly introduced water from the inlet undergoes progressive preheating via the first and second heat exchangers. The refrigerant liquid is cooled by the first heat exchanger, significantly increasing its subcooling. The various systems complement each other, greatly improving the heat pump system's energy efficiency ratio, enhancing operational reliability, and saving energy. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the overall system structure of the present invention.

[0069] Figure 2 This is a connection framework diagram of the electrical control system.

[0070] Figure 3 This is a schematic diagram of the refrigerant circulation system.

[0071] Figure 4 This is a schematic diagram of the structure of a cascade preheating system.

[0072] Figure 5 This is a schematic diagram of an energy storage and steam generation system.

[0073] Figure 6 This is a schematic diagram of a hot water circulation system. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0075] Please see Figure 1 The present invention provides a technical solution: a cascade preheating and energy storage steam heat pump unit, comprising a refrigerant circulation system 1, a cascade preheating system 2, an energy storage and steam generation system 3, and a hot water circulation system 4;

[0076] The refrigerant circulation system 1 includes a refrigerant compressor 11, a condenser 12, an expansion valve 13, and an evaporator 14 connected in sequence by pipes to form a closed loop;

[0077] The cascade preheating system 2 includes an inlet 21, a first water pump 22 and a heat exchange assembly connected in sequence by pipes. The heat exchange assembly is connected between the condenser 12 and the expansion valve 13.

[0078] The energy storage and steam generation system 3 includes an energy storage flash tank 31, a second regulating valve 32, a steam compressor 33, and a steam outlet 34, which are connected in sequence by pipelines.

[0079] The hot water circulation system 4 includes a second water pump 41 and a first regulating valve 42. The second water pump 41 and the first regulating valve 42 are connected to the energy storage flash tank 31 and the condenser 12 through pipelines and form a closed loop.

[0080] The heat exchange component is connected between the second water pump 41 and the energy storage flash tank 31 via a pipeline.

[0081] To facilitate step-by-step preheating and improve energy utilization, in this embodiment, preferably, the heat exchange assembly includes a first heat exchanger 23 and a second heat exchanger 24 connected to each other. The first heat exchanger 23 is connected between the condenser 12 and the expansion valve 13. The first water pump 22 and the second heat exchanger 24 are connected through the first heat exchanger 23. The second heat exchanger 24 is connected between the second water pump 41 and the energy storage flash tank 31 through a pipe. The oil inlet and outlet of the refrigerant compressor 11 are connected to the oil inlet and outlet of the second heat exchanger 24 through oil pipes to form a closed loop. The purpose is that the lubricating oil used by the refrigerant compressor 11 needs to have a certain viscosity. However, the lubricating oil separated after the refrigerant compressor 11 is working has a high temperature and cannot guarantee the viscosity of the lubricating oil. Therefore, it needs to be cooled. The lubricating oil is cooled by heat exchange through the second heat exchanger 24, while the water temperature is increased to achieve a further preheating effect.

[0082] In order to provide a backup pipeline in case of equipment failure or when replacement and maintenance are required, in this embodiment, preferably, a bypass valve 15 is connected between the oil outlet pipe and the oil inlet pipe of the refrigerant compressor 11. The bypass pipeline serves as a backup pipeline, and its function is to isolate the equipment when it fails or needs to be replaced and maintained, or to close the main pipeline and open the bypass pipeline to allow the equipment to continue operating.

[0083] To facilitate improved intelligent control, this embodiment preferably includes an electrical control system 5, which includes:

[0084] Sensor components used to sense temperature, pressure, or liquid level at a target location;

[0085] The sensor data acquisition module 51 is connected to the sensor assembly and is used to acquire the data sensed by the sensor assembly.

[0086] The central controller 52 is connected to the sensor data acquisition module 51 and is used to process and analyze the acquired data and send control commands to the controlled devices through preset control parameters. The controlled devices include a refrigerant compressor 11, a first water pump 22, a second water pump 41, a first regulating valve 42, a second regulating valve 32, a bypass valve 15, a steam compressor 33, and a water pump speed regulator 53 that controls the opening of the first water pump 22.

[0087] The display operation module 54 is connected to the central controller 52 and is used to set preset control parameters.

[0088] To facilitate monitoring of temperature, pressure, or liquid level at various locations within the unit, in this embodiment, preferably, the sensor assembly includes a third temperature sensor 501, a fifth temperature sensor 502, a first pressure sensor 503, a second pressure sensor 504, a third pressure sensor 505, and a liquid level sensor 506. The third temperature sensor 501 is installed on the connecting pipe between the second regulating valve 32 and the steam compressor 33. The fifth temperature sensor 502 is installed at the bottom of the energy storage flash tank 31. The first pressure sensor 503 is installed on the connecting pipe between the condenser 12 and the first regulating valve 42. The second pressure sensor 504 is installed on the connecting pipe between the energy storage flash tank 31 and the second regulating valve 32. The third pressure sensor 505 is installed on the connecting pipe between the second regulating valve 32 and the steam compressor 33. The liquid level sensor 506 is installed inside the energy storage flash tank 31.

[0089] To facilitate further monitoring of temperature or pressure at various locations within the unit, in this embodiment, preferably, the sensor assembly further includes a first temperature sensor 507, a second temperature sensor 508, a fourth temperature sensor 509, a sixth temperature sensor 510, and a fourth pressure sensor 511. The first temperature sensor 507 is installed on the connecting pipe between the second water pump 41 and the condenser 12; the second temperature sensor 508 is installed on the connecting pipe between the condenser 12 and the first regulating valve 42; the fourth temperature sensor 509 is installed on the connecting pipe between the oil outlet of the refrigerant compressor 11 and the oil interface of the second heat exchanger 24; the sixth temperature sensor 510 is installed on the top of the energy storage flash tank 31; and the fourth pressure sensor 511 is installed on the connecting pipe between the steam compressor 33 and the steam outlet 34. The sensor assembly may also include a refrigerant compressor overload protector 512 installed on the refrigerant compressor 11, a first water pump overload protector 513 installed on the first water pump 41, and a second water pump overload protector 514 installed on the second water pump 41, the purpose of which is to prevent the components from overheating and being damaged due to overload.

[0090] The present invention also provides a control method for a cascade preheating energy storage steam heat pump unit;

[0091] In order to enable free switching between heat storage, energy storage, and direct heating, in this embodiment, preferably, the display operation module 54 is equipped with three operating modes corresponding to three different preset control parameters, including an energy storage operation mode that introduces hot water into the energy storage flash tank 31 and circulates and heats the hot water in the energy storage flash tank 31, an energy storage steam generation mode that uses the hot water inside the energy storage flash tank 31 for evaporation, and a direct steam generation mode, and the three operating modes can be switched freely.

[0092] In order to facilitate the storage of hot water inside the energy storage flash tank 31, in this embodiment, preferably, when the energy storage operation mode is selected, the central controller 52 controls the second regulating valve 32 to close and controls the refrigerant compressor 11, the first water pump 22 and the second water pump 41 to start working.

[0093] The actual liquid level measured by the level sensor 506 is H. 实测液位 The liquid level setpoint is H. 液位设定 The control accuracy is H 设定精度 Set H on the display operation module 54 液位设定 and H 液位精度 ;

[0094] When H 液位设定 -H 设定精度 ≤H 实测液位 ≤H 液位设定 +H 设定精度 At this time, the water pump speed regulator 53 remains in its original state;

[0095] When H 实测液位 >H 液位设定 +H 设定精度 At that time, the central controller 52 controls the water pump speed regulator 53 to reduce the opening degree of the first water pump 22;

[0096] When H 实测液位 <H 液位设定 -H 设定精度 At that time, the central controller 52 controls the water pump speed regulator 53 to increase the opening degree of the first water pump 22;

[0097] The actual measured pressure of the first pressure sensor 503 is P. 实测压力1 The pressure setpoint is P. 压力设定1 The control accuracy is P 设定精度1 Set P on the display operation module 54 压力设定1 and P 设定精度1 ;

[0098] When P 压力设定1 -P 设定精度1 ≤P 实测压力1 ≤P 压力设定1 +P 设定精度1 At this time, the first regulating valve 42 remains in its original state;

[0099] When P 实测压力1 >P 压力设定1 +P 设定精度1 At that time, the central controller 52 controls the first regulating valve 42 to increase its opening degree;

[0100] When P 实测压力1 <P 压力设定1 -P 设定精度1 At that time, the central controller 52 controls the first regulating valve 42 to reduce its opening;

[0101] The actual measured temperature of the fifth temperature sensor 502 is T. 实测温度5 The temperature setpoint is T. 温度设定5 The control accuracy is T 设定精度5 Set T on the display operation module 54 温度设定5 and T 设定精度5 ;

[0102] When T 温度设定5 -T 设定精度5 ≤T 实测温度5 ≤T 温度设定5 +T 设定精度5 At this time, the refrigerant compressor 11 remains in its original state;

[0103] When T 实测温度5 >T 温度设定5 +T 设定精度5 At that time, the central controller 52 controls the refrigerant compressor 11 to operate;

[0104] When T 实测温度5 <T 温度设定5 -T 设定精度5 At that time, the central controller 52 controls the refrigerant compressor 11 to load.

[0105] To facilitate evaporation using the hot water inside the energy storage flash tank 31, in this embodiment, preferably,

[0106] When the energy storage steam generation mode is selected, the central controller 52 controls the second regulating valve 32 to open and controls the refrigerant compressor 11, the first water pump 22 and the second water pump 41 to stop.

[0107] The actual liquid level measured by the level sensor 506 is H. 实测液位 The liquid level stop function uses the energy storage mode setting value H. 液位停止用储能设定 Set H on the display operation module 54 液位停止用储能设定 ;

[0108] When H 实测液位 >H 液位停止用储能设定 At that time, continue operating in the energy storage steam generation mode;

[0109] When H 实测液位 ≤H 液位停止用储能设定 At that time, the control unit switches to direct steam generation mode;

[0110] The steam can be controlled by pressure or temperature on the display operation module 54.

[0111] When steam is set to be controlled by pressure;

[0112] The third pressure sensor 505 actually measures pressure P. 实测压力3The pressure setpoint is P. 压力设定3 The control accuracy is P 设定精度3 Set P on the display operation module 54 压力设定3 and P 设定精度3 ;

[0113] When P 压力设定3 -P 设定精度3 ≤P 实测压力3 ≤P 压力设定3 +P 设定精度3 At this time, the second regulating valve 32 remains in its original state;

[0114] When P 实测压力3 >P 压力设定3 +P 设定精度3 At that time, the central controller 52 controls the second regulating valve 32 to reduce the opening degree;

[0115] When P 实测压力3 <P 压力设定3 -P 设定精度3 At that time, the central controller 52 controls the second regulating valve 32 to increase its opening degree;

[0116] When steam is set to be controlled by temperature;

[0117] The actual measured temperature of the third temperature sensor 501 is T. 实测温度3 The temperature setpoint is T. 温度设定3 The control accuracy is T 设定精度3 Set T on the display operation module 54 温度设定3 and T 设定精度3 ;

[0118] When T 温度设定3 -T 设定精度3 ≤T 实测温度3 ≤T 温度设定 3+T 设定精度3 At this time, the second regulating valve 32 remains in its original state;

[0119] When T 实测温度3 >T 温度设定3 +T 设定精度3 At that time, the central controller 52 controls the second regulating valve 32 to reduce the opening degree;

[0120] When T 实测温度3 <T 温度设定3 -T 设定精度3 At that time, the central controller 52 controls the second regulating valve 32 to increase its opening.

[0121] To facilitate the direct generation of steam after the hot water inside the energy storage flash tank 31 is used up, in this embodiment, preferably,

[0122] When the direct steam generation mode is set, the central controller 52 controls the second regulating valve 32 to open, and controls the refrigerant compressor 11, the first water pump 22 and the second water pump 41 to open.

[0123] The actual liquid level measured by the level sensor 506 is H. 实测液位 The liquid level setpoint is H. 液位设定 The control accuracy is H 设定精度 Set H on the display operation module 54 液位设定 and H 液位精度 ;

[0124] When H 液位设定 -H 设定精度 ≤H 实测液位 ≤H 液位设定 +H 设定精度 At this time, the water pump speed regulator 53 remains in its original state;

[0125] When H 实测液位 >H 液位设定 +H 设定精度 At that time, the central controller 52 controls the water pump speed regulator 53 to reduce the opening degree of the first water pump 22;

[0126] When H 实测液位 <H 液位设定 -H 设定精度 At that time, the central controller 52 controls the water pump speed regulator 53 to increase the opening degree of the first water pump 22;

[0127] The steam can be controlled by pressure or temperature on the display operation module 54.

[0128] When steam is set to be controlled by pressure;

[0129] The third pressure sensor 505 actually measures pressure P. 实测压力3 The pressure setpoint is P. 压力设定3 The control accuracy is P 设定精度3 Set P on the display operation module 54 压力设定3 and P 设定精度3 ;

[0130] When P 压力设定3 -P 设定精度3 ≤P 实测压力3 ≤P 压力设定3 +P 设定精度3 At this time, the refrigerant compressor 11 remains in its original state;

[0131] When P 实测压力3 >P 压力设定3 +P 设定精度3 At that time, the central controller 52 controls the refrigerant compressor 11 to operate;

[0132] When P实测压力3 <P 压力设定3 -P 设定精度3 At that time, the central controller 52 controls the refrigerant compressor 11 to load;

[0133] When steam is set to be controlled by temperature;

[0134] The actual measured temperature of the third temperature sensor 501 is T. 实测温度3 The temperature setpoint is T. 温度设定3 The control accuracy is T 设定精度3 Set T on the display operation module 54 温度设定3 and T 设定精度3 ;

[0135] When T 温度设定3 -T 设定精度3 ≤T 实测温度3 ≤T 温度设定3 +T 设定精度3 At this time, the refrigerant compressor 11 remains in its original state;

[0136] When T 实测温度3 >T 温度设定3 +T 设定精度3 At that time, the central controller 52 controls the refrigerant compressor 11 to operate;

[0137] When T 实测温度3 <T 温度设定3 -T 设定精度3 At that time, the central controller 52 controls the refrigerant compressor 11 to load.

[0138] The working principle and usage process of this invention: Please refer to [link / reference]. Figure 3 In the refrigerant circulation system 1, the refrigerant compressor 11 compresses the low-temperature, low-pressure gaseous working fluid into a high-temperature, high-pressure gas, which then passes through the condenser 12. In the condenser 12, the gaseous working fluid releases heat and condenses into a high-temperature, high-pressure liquid. After being throttled by the expansion valve 13, the liquid becomes a low-temperature, low-pressure liquid. The low-temperature, low-pressure liquid working fluid is sent to the evaporator 14, where it absorbs heat and evaporates to become a low-temperature, low-pressure gas. The gaseous working fluid then re-enters the refrigerant compressor 11, thus completing the refrigerant circulation.

[0139] Please see Figure 4In the cascade preheating system 2, the first water pump 22 drives water inlet 21, causing the liquid water to flow sequentially through the first heat exchanger 23 and the second heat exchanger 24 for step-by-step preheating. After passing through the first heat exchanger 23, the liquid water changes from a low temperature to a medium temperature; after passing through the second heat exchanger 24, it changes to a medium-high temperature. Then, driven by the second water pump 41, the liquid water flows through the condenser 12 to absorb heat and change to a high temperature. The lubricating oil used in the refrigerant compressor 11 needs to have a certain viscosity, and the lubricating oil separated after the refrigerant compressor 11 operates... The lubricating oil temperature is too high, making it impossible to maintain the correct viscosity. Therefore, cooling is required. The lubricating oil is cooled by heat exchange through the second heat exchanger 24. While cooling the lubricating oil through the second heat exchanger 24, the preheating temperature of the liquid water can be increased. The preheating temperature of the liquid water through the first heat exchanger 23 can also increase the subcooling of the working fluid, thereby improving energy utilization. The various systems complement each other, significantly improving the energy efficiency ratio of the heat pump system, enhancing operational reliability, and saving energy consumption.

[0140] Please see Figure 6 In the hot water circulation system 4, the second water pump 41 drives the liquid water in the second heat exchanger 24 to enter the condenser 12 for heating. After heating, the water flows into the energy storage flash tank 31 through the first regulating valve 42. At the same time, it drives the cooled hot water in the energy storage flash tank 31 during long-term shutdown to enter the condenser 12 for supplemental heating. Finally, the water flows back into the energy storage flash tank 31 through the first regulating valve 42 to prevent the water temperature in the energy storage flash tank 31 from being too low to boil and generate steam when restarting after a shutdown.

[0141] Please see Figure 5 In the energy storage and steam generation system 3, the hot water in the energy storage flash tank 31 enters the steam compressor 33 through the second regulating valve 32 and is finally ejected from the steam outlet 34.

[0142] By monitoring temperature, pressure, and liquid level at various locations within the unit using sensors, the controlled components are adjusted to maintain system balance and improve system reliability. Please refer to [link to relevant documentation]. Figure 2 In the electrical control system 5, preset control parameters are set through the display operation module 54, the temperature, pressure or liquid level of the target position is sensed by the sensor component, the data sensed by the sensor component is collected by the sensor data acquisition module 51 and sent to the central controller 52. The central controller 52 processes and analyzes the collected data and sends control commands to the controlled devices through the preset control parameters, thereby driving the water pump speed controller 53, refrigerant compressor 11, first water pump 22, second water pump 41, first regulating valve 42 and second regulating valve 32 to make corresponding adjustment actions, and finally achieve a state in which the measured value and the set value are relatively balanced, with a higher degree of intelligence.

[0143] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cascade preheating energy storage steam heat pump unit, characterized in that: The refrigerant circulation system (1), the cascade preheating system (2), the energy storage and steam generation system (3) and the hot water circulation system (4) are connected by pipelines in sequence and form a closed loop. The refrigerant circulation system (1) comprises a refrigerant compressor (11), a condenser (12), an expansion valve (13) and an evaporator (14) connected by pipelines in sequence and forming a closed loop. The cascade preheating system (2) comprises a water inlet (21), a first water pump (22) and a heat exchange assembly connected by pipelines in sequence. The energy storage and steam generation system (3) comprises an energy storage flash tank (31), a second regulating valve (32), a steam compressor (33) and a steam outlet (34) connected by pipelines in sequence. The hot water circulation system (4) comprises a second water pump (41) and a first regulating valve (42) both connected by pipelines between the energy storage flash tank (31) and the condenser (12) and forming a closed loop. The heat exchange assembly is connected by pipelines between the second water pump (41) and the energy storage flash tank (31). The heat exchange assembly comprises a first heat exchanger (23) and a second heat exchanger (24) connected to each other, the second heat exchanger (24) is used for heat exchange and cooling of lubricating oil while increasing the temperature of water, the first heat exchanger (23) is connected between the condenser (12) and the expansion valve (13), the first water pump (22) and the second heat exchanger (24) are connected through the first heat exchanger (23), the second heat exchanger (24) is connected by pipelines between the second water pump (41) and the energy storage flash tank (31), and the oil outlet of the refrigerant compressor (11) and the oil inlet of the second heat exchanger (24) are connected by oil pipes to form a closed loop. The bypass valve (15) is connected between the oil outlet pipe of the refrigerant compressor (11) and the oil inlet pipe of the refrigerant compressor (11). The electrical control system (5) comprises: A sensor assembly for sensing the temperature, pressure or liquid level of the target position; A sensor data acquisition module (51) connected with the sensor assembly for acquiring data sensed by the sensor assembly; A central controller (52) connected with the sensor data acquisition module (51) for processing and analyzing the acquired data and sending control instructions to controlled devices through preset control parameters, the controlled devices including a water pump speed regulator (53) for controlling the opening degree of the first water pump (22), the refrigerant compressor (11), the first water pump (22), the second water pump (41), the first regulating valve (42) and the second regulating valve (32) are all controlled devices; A display operation module (54) connected with the central controller (52) for setting the preset control parameters. The sensor assembly comprises a third temperature sensor (501), a fifth temperature sensor (502), a first pressure sensor (503), a second pressure sensor (504), a third pressure sensor (505) and a liquid level sensor (506), the third temperature sensor (501) is installed on a connecting pipeline between the second regulating valve (32) and the steam compressor (33), the fifth temperature sensor (502) is installed at the bottom of the energy storage flash tank (31), the first pressure sensor (503) is installed on a connecting pipeline between the condenser (12) and the first regulating valve (42), the second pressure sensor (504) is installed on a connecting pipeline between the energy storage flash tank (31) and the second regulating valve (32), the third pressure sensor (505) is installed on a connecting pipeline between the second regulating valve (32) and the steam compressor (33), and the liquid level sensor (506) is installed inside the energy storage flash tank (31); The sensor assembly further comprises a first temperature sensor (507), a second temperature sensor (508), a fourth temperature sensor (509), a sixth temperature sensor (510) and a fourth pressure sensor (511), the first temperature sensor (507) is installed on a connecting pipeline between the second water pump (41) and the condenser (12), the second temperature sensor (508) is installed on a connecting pipeline between the condenser (12) and the first regulating valve (42), the fourth temperature sensor (509) is installed on a connecting pipeline between the refrigerant compressor (11) oil outlet and the second heat exchanger (24) oil interface, the sixth temperature sensor (510) is installed at the top of the energy storage flash tank (31), and the fourth pressure sensor (511) is installed on a connecting pipeline between the steam compressor (33) and the steam outlet (34).

2. A control method for a step preheating energy storage steam heat pump unit according to claim 1, characterized in that: The display operation module (54) is provided with three different preset control parameters, including an energy storage operation mode, an energy storage steam generation mode and a direct steam generation mode, and the three operation modes can be freely switched.

3. The control method of the cascade preheating energy storage steam heat pump unit according to claim 2, characterized in that: when the energy storage operation mode is selected, the central controller (52) controls the second regulating valve (32) to be closed, and controls the refrigerant compressor (11), the first water pump (22) and the second water pump (41) to start working; The liquid level sensor (506) actually tests the liquid level as H 实测液位 , the liquid level set value as H 液位设定 , the control precision as H 设定精度 , and H 液位设定 and H 液位精度 are set on the display operation module (54). When H 液位设定 - H 设定精度 ≤ H 实测液位 ≤ H 液位设定 + H 设定精度 , the water pump governor (53) remains in the original state; When H 实测液位 > H 液位设定 + H 设定精度 , the central controller (52) controls the water pump speed regulator (53) to reduce the opening of the first water pump (22); When H 实测液位 <H 液位设定 -H 设定精度 the central controller (52) controls the water pump speeder (53) to increase the opening of the first water pump (22); The first pressure sensor (503) actually tests pressure P 实测压力1 , the pressure set value is P 压力设定1 , the control precision is P 设定精度1 , P 压力设定1 and P 设定精度1 are set on the display operation module (54); When P 压力设定1 - P 设定精度1 ≤ P 实测压力1 ≤ P 压力设定1 + P 设定精度1 , the first regulating valve (42) remains in the original state; When P 实测压力1 > P 压力设定1 + P 设定精度1 , the central controller (52) controls the first regulating valve (42) to increase the opening degree; When P 实测压力1 When P 压力设定1 When P 设定精度1 The central controller (52) controls the first regulating valve (42) to reduce the opening degree. The fifth temperature sensor (502) actually tests temperature T 实测温度5 , the temperature set value is T 温度设定5 , the control precision is T 设定精度5 , T 温度设定5 and T 设定精度5 are set on the display operation module (54). When T 温度设定5 - T 设定精度5 ≤ T 实测温度5 ≤ T 温度设定5 + T 设定精度5 , the refrigerant compressor (11) remains in the original state; When T 实测温度5 > T 温度设定5 + T 设定精度5 , the central controller (52) controls the refrigerant compressor (11) to be loaded; When T 实测温度5 <T 温度设定5 -T 设定精度5 The central controller (52) controls the refrigerant compressor (11) to be loaded.

4. The control method of the cascade preheating energy storage steam heat pump unit according to claim 2, characterized in that: when the energy storage steam generation mode is selected, the central controller (52) controls the second regulating valve (32) to be opened, and controls the refrigerant compressor (11), the first water pump (22) and the second water pump (41) to be stopped; The liquid level sensor (506) actually tests the liquid level as H 实测液位 , and the liquid level stop energy storage mode set value is H 液位停止用储能设定 , and H 液位停止用储能设定 is set on the display operation module (54). When H 实测液位 > H 液位停止用储能设定 , continue to operate in the energy storage steam generation mode; When H 实测液位 ≤ H 液位停止用储能设定 the machine group is controlled to go to direct steam generation mode; the steam pressure or temperature is set as the control target on the display operation module (54); when the steam pressure is set as the control target; The third pressure sensor (505) actually tests pressure P 实测压力3 , the pressure set value is P 压力设定3 , the control precision is P 设定精度3 , P 压力设定3 and P 设定精度3 are set on the display operation module (54); When P 压力设定3 - P 设定精度3 ≤ P 实测压力3 ≤ P 压力设定3 + P 设定精度3 , the second regulating valve (32) remains in the original state; When P 实测压力3 > P 压力设定3 + P 设定精度3 , the central controller (52) controls the second regulating valve (32) to reduce the opening degree; When P 实测压力3 When P 压力设定3 When P 设定精度3 the central controller (52) controls the second regulating valve (32) to increase the opening degree. when the steam temperature is set as the control target; The third temperature sensor (501) actually tests temperature T 实测温度3 , the temperature set value is T 温度设定3 , the control precision is T 设定精度3 , T 温度设定3 and T 设定精度3 are set on the display operation module (54). When T 温度设定3 -T 设定精度3 ≤T 实测温度3 ≤T 温度设定 3+T 设定精度3 , the second regulating valve (32) remains in the original state; When T 实测温度3 > T 温度设定3 + T 设定精度3 , the central controller (52) controls the second regulating valve (32) to reduce the opening degree; When T 实测温度3 When T 温度设定3 When T 设定精度3 The central controller (52) controls the second regulating valve (32) to increase the opening degree.

5. The control method of the step preheating energy storage steam heat pump unit according to claim 2, characterized in that: when the direct steam generation mode is set, the central controller (52) controls the second regulating valve (32) to open, and controls the refrigerant compressor (11), the first water pump (22) and the second water pump (41) to open; The liquid level sensor (506) actually tests the liquid level as H 实测液位 , the liquid level set value as H 液位设定 , the control precision as H 设定精度 , and H 液位设定 and H 液位精度 are set on the display operation module (54). When H 液位设定 - H 设定精度 ≤ H 实测液位 ≤ H 液位设定 + H 设定精度 , the water pump governor (53) remains in the original state; When H 实测液位 > H 液位设定 + H 设定精度 the central controller (52) controls the water pump governor (53) to reduce the opening degree of the first water pump (22); When H 实测液位 <H 液位设定 -H 设定精度 the central controller (52) controls the water pump speeder (53) to increase the opening of the first water pump (22); setting the steam to be controlled by pressure or temperature on the display operation module (54); when the steam is set to be controlled by pressure; The third pressure sensor (505) actually tests pressure P 实测压力3 , the pressure set value is P 压力设定3 , the control precision is P 设定精度3 , P 压力设定3 and P 设定精度3 are set on the display operation module (54); When P 压力设定3 - P 设定精度3 ≤ P 实测压力3 ≤ P 压力设定3 + P 设定精度3 , the refrigerant compressor (11) remains in the original state; When P 实测压力3 > P 压力设定3 + P 设定精度3 , the central controller (52) controls the refrigerant compressor (11) to be loaded; When P 实测压力3 When P 压力设定3 When P 设定精度3 The central controller (52) controls the refrigerant compressor (11) to be loaded. when the steam is set to be controlled by temperature; The third temperature sensor (501) actually tests temperature T 实测温度3 , the temperature set value is T 温度设定3 , the control precision is T 设定精度3 , T 温度设定3 and T 设定精度3 are set on the display operation module (54). When T 温度设定3 - T 设定精度3 ≤ T 实测温度3 ≤ T 温度设定3 + T 设定精度3 , the refrigerant compressor (11) remains in the original state; When T 实测温度3 > T 温度设定3 + T 设定精度3 , the central controller (52) controls the refrigerant compressor (11) to be loaded; When T 实测温度3 When T 温度设定3 When T 设定精度3 The central controller (52) controls the refrigerant compressor (11) to be loaded.

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